Do you relish rising with the sun, or do you come alive most after dark? There are benefits to both. Early risers may be better planners, whereas night owls may be more creative. Your genetics can play a role in determining what type of chronotype you have. (Chronotype is your body's preference for being a morning person or a night person.) But environment and lifestyle can affect your internal clock — your biological sleep-wake cycle, too. An AncestryDNA^® Traits test can tell you how your DNA might affect whether you're a morning lark or a night owl.

What Does it Mean to be a Morning Person or a Night Person?

Morning people, often called early birds, tend to go to bed early and wake up early. They may not need an alarm clock. They have their most energy early in the day, and tire in the late afternoon and evening. By contrast, if you're a night person, or a night owl, you likely enjoy staying up late, sleeping late, and hitting the snooze button. Night people tend to feel better later in the day, especially at night.

Understanding these individual tendencies means looking at the different sleep chronotypes. Researchers have identified at least three: the morning chronotype, the evening chronotype, and the chronotype that is neither morning nor evening. In reality, many people fall into the "neither" category, which means they are not motivated by either extreme. In fact, research has found that about 40% of adults are either morning people or night people, but 60% are neither. Your sleep pattern may also change throughout your life.

The Genetics Behind Whether You're a Morning or Night Person

Researchers have been trying to understand how much genetics contribute to your body's natural sleep-wake cycle. We know that our cells have molecular "clocks" that attune themselves to a 24-hour cycle. This internal cell clock tells us when we are sleepy. In 1994, scientists discovered a protein called CLOCK that is key in creating these 24-hour cycles (called circadian rhythms) in humans and other mammals.

But the search for which genes are specifically related to chronotype continues. Looking at genome-wide data is one way researchers are narrowing these genes down. One study found more than 350 gene locations that may be associated with being a morning person. AncestryDNA^® scientists are looking at the DNA of early risers and night owls, too. After surveying 770,000 people about their sleep schedule, and then comparing their DNA with their responses, AncestryDNA^® scientists found more than 43,000 DNA markers connected to being a morning or night person, which they used to build (a predictive model called) a Polygenic Risk Score.

What Else Does Science Say About Morning People or Night People?

Whether you sleep in or rise with the sun is influenced by many factors. The older you are, the more likely you are to be a morning person. And along with that, young adults and teenagers are more likely to be night owls. When it comes to biological sex, men tend to be evening people more than women. Of course, signals from your surroundings, like how much light there is, matter, too. Waning natural light makes your brain produce the sleep hormone melatonin.

Researchers have conducted many studies to tease out the benefits and risks of being either a morning person or an evening person. One study found that evening people may be more at risk for developing diabetes, respiratory and gastrointestinal disorders, and having mental health problems. This may be because they don't get enough sleep or exercise, and may eat less healthy foods. Another study found that night owls may be more visually creative. As for morning people, they may be more persistent and self-directed.

Interesting Facts About Being an Early Bird or a Night Owl

If you think about the evolution of human beings, it makes sense that the world is full of both morning people and night people—and that biology helps determine this. Having some people be more alert during the day and some people be more alert at night helped our ancestors survive, especially those in hunter-gatherer societies, where danger was always lurking. Our ancestors most likely shared the task of vigilance. Researchers call this the sentinel hypothesis.

Hence, there's nothing biologically damaging about being a night owl. In fact, it played an important role in our evolution. The problem is that it doesn't jive very well with the way the world is set up now, like the typical 9-to-5 work schedule. So, all those studies that link being an evening person to disease or depression? It's more likely because of the misalignment of a person's natural circadian rhythm with cultural expectations. In other words, for night owls, it's difficult to live in a world organized around early birds (or at least people who don't mind getting up in the morning).

References

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